In this paper I will provide a hylomorphic critique of Jeff McMahan’s “An Alternative to Brain Death.” I will evaluate three puzzles—the dicephalus, the braintransplant, and the split-brain phenomenon—proposed by McMahan which allow him to deny that a human being is identical to an organism. I will contend thatMcMahan’s solution entails counterintuitive consequences that pose problems to organ transplant cases. A Thomistic hylomorphic metaphysics not only avoids these unwelcome consequences and provides solutions to the three puzzles but in doing so allows for an alternative definition of death. Since McMahan has constructed his definition of death around his own metaphysics, alternative metaphysics, in this case a hylomorphic metaphysics, allow for an alternative definition of death